3D imaging

This week a powerful image from Ken Williams ofShadows and Stone (copyrighted, used with permission) lit up the Irish Rock Art Facebook Page (180,000 people had seen it at last count, and it’s been shared more than 1500 times). The photograph, taken with Ken’s signature blend of natural and artificial light, was of a stone in Kerry often known as the Staigue Bridge Rock Art, although technically it’s in the townland of Liss.

As it turns out, this is one of the best-documented rock art panels in Ireland, with images dating from the middle of the nineteenth century to the present day.

Taken on a recent visit to Liss/Staigue Bridge Rock Art site. This is probably what a casual visitor will see. Can you make out any carvings?

The response to this photograph highlights several important features of Irish rock art. First of all, it seems people are hungry to know more about these enigmatic carvings, and yet rock art is one of the least known aspects of Irish archaeology. Time after time, as Robert and I present exhibitions or give talks, we meet up with a near-universal response of “How come we’ve never heard about this before?”

Another view of the top section of the panel

Secondly, a photograph like this is not normally what you observe in the field. Commonly, rock art (and this one is no exception) is actually difficult to see under most lighting conditions. This rock is just off a popular hiking trail and the vast majority of walkers are unaware of what is a few meters from their path. Even if the route went right alongside it, most walkers would pass by without noticing anything unusual.

This will give you an idea of the extent of the panel

Thirdly, it is no longer possible to record rock art by any of the traditional methods that were in common use up to the 1990s. Nowadays, recording techniques that do not impact in any way with the rock surface are preferred, and that limits us to what can be imaged through photographic and scanning technology.

There are currently three ways in common use to photograph rock art so that the carvings will show up. The first is to use the natural low, slanting, shadow-casting, light at sunrise or sunset. Rock Art Kerry, the work of archaeologist Aoibheann Lambe, has an outstanding photograph of the rock surface using only natural light. Given our climate, it is likely that many visits to the rock in all kinds of temperatures, early in the morning or late in the evening, were necessary before the perfect shot was possible. Aoibheann’s Facebook page is the place to be these days for new finds – she is making discoveries at a breathtaking pace!

The second is to use flash photography – a technique that Ken Williams has perfected and uses to great effect to show up even faint carvings. We’ve seen Ken working – this isn’t a mater of a simple flash on a camera – multiple flashes are deployed with a skill that comes from long experience, and respond to an electronic trigger on his camera.If you haven’t already done so, a visit to his site is an absolute must for anyone interested in rock art – or indeed in Irish archaeology.

Finola and Robert from Roaringwater Journal and Ken Williams of Shadows and Stone at Derrynablaha in Kerry

It is particularly exciting because it’s unusually clear (rock art 3D images can suffer from lack of clarity for a variety of reason) and also because this technique allows an image of the whole panel, whereas photography can only capture pieces at a time.

But back to the past, when it was still possible to produce drawings of the carvings. Back, in fact, to the 1850s! There were two Irish antiquarians called the Rev Graves. The better-known one was the Rev James Graves of Kilkenny, but the one we are concerned with here was the Rev Charles Graves, Bishop of Limerick and a noted mathematician, scholar, antiquarian, and President of the Royal Irish Academy. He was fascinated by Ogham and on a trip to view Ogham stones in Kerry he came across other ‘inscribed rocks’ of a type he was unfamiliar with. He wrote up his findings and presented them to the Academy in 1860.

Taken from the Wikipedia article on Charles Graves. Image above by Anonymous – Church Bells (1874–1875)) W. Wells Gardner, Publisher, London, Public Domain

The good Bishop had none of our modern scruples about interfering with the rock surface, or removing the turf to see what else he could fine. He did both: three feet of turf was stripped back to reveal the extent of the carvings and a rubbing was made from the whole surface, which was later converted to a survey-drawing. This, to this day, is the only drawing we have of the complete carving.

When I wrote my thesis on The Rock Art of Cork and Kerry in 1973 I said this about Charles Graves:

The first paper devoted to rock art in Ireland was by Rev. Charles Graves. In 1860 he read a paper to the Royal Irish Academy entitled “On a previously undescribed Class of Monuments”.His paper, mainly concerned with Co. Kerry, is still very valuable and his drawings and observations are often more accurate and more reliable than many later accounts.

My own drawing was done in 1972. The technique I used then was to chalk in the carvings and trace them onto clear plastic film. That tracing was then re-traced on to good quality paper using indian ink and a stipple technique and then photographically reduced by a professional printing firm. It is naturally an imperfect and subjective method, but long practice enabled me to produce surprisingly accurate renditions which stand up well to modern recording techniques.

I confined my drawing to the main area of carving and used Graves’ drawing as an additional illustration

There are few examples of Irish rock art with the pedigree of Staigue Bridge. It is classic cup-and-ring art in its execution but also contains the unusual elements of very large circles surrounding small cupmarks. It is enormous – a fact that would never have been appreciated if Graves had not determined to find the true extent of the carved surface (although of course we do NOT condone this practice now). It has a literature that goes back a century and a half, and was one of the first pieces of Irish rock art to be described and illustrated. It’s a national treasure.